Assert on Arrays

Assert on Arrays

Problem Description:

#include<stdio.h>
#include<assert.h>
const char *authour ="Alexandre Santos";
int ints_get(int *a)
{
    int result = 0;
    int x;
    while (scanf("%d", &x) !=EOF)
    {
        a[result++] = x;
    }
    return result;
}


int sum_odd(const int *a, int n)
{
    int sum = 0;
    for(int i = 0; i < n; i++)
        if(i%2 != 0)
            sum += a[i];
    return sum;
}
int sum_all(const int *a, int n)
{
    int sum = 0;
    for(int i = 0; i < n; i++)
        sum = sum + a[i];
    return sum;
}

int final(const int *a, int n)
{
    return sum_all(a,n) - sum_odd(a,n);
}

void unit_test_even_values_minus_odd_values(void){
    int a1[8] = {1,2,3,4,5,6,7,8};
    assert(final(a1, 8) == 4);
    assert(final(a1, 6) == 3);
    assert(final(a1, 4) == 2);
    assert(final(a1, 2) == 1); 
}

void unit_tests(void){
    unit_test_even_values_minus_odd_values();
}


void test_sum(void)
{
    int a[100];
    int n = ints_get(a);
    int total = final(a,n);
    printf("%dn", total);
}



int main()
{
    test_sum();
    return 0;
}

I have this program but I don’t understand how the assertions work here, my main question is what the second number represents. For example I understand that assert(final(a1, 8) == 4) I understand that a1 is the array determined in the line above but I can’t understand the second number (8)…. Can anyone explain to me how this works? I tried to search a little bit but I still don’t understand…

Solution – 1

The second argument to final is the number of values to work on from that array, starting from the beginning.

final(a1, 8) sums all eight values. final(a1, 6) only sums the first six values.